• observes_depths@aussie.zone
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    2 days ago

    Imagine if speed limits were variable based on a car’s weight and lethality. Only small cars are allowed to go fast.

    • boonhet@sopuli.xyz
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      1 day ago

      It’d be a difficult calculation to make. Bigger cars usually have better brakes and wider tires and in sporty trim levels of premium cars those can even help them stop faster than smaller cars.

      Audi RS4 with it’s sporty brakes, stops 1800 KG down from 140 km/h to 0 in 65 meters. Corolla 1.8 hybrid will do 130 to 0 in 66. Weighs about 1400 KG. Yes I cherrypicked it, but that’s the point.

      The extra weight actually helps grip so that cancels it out somewhat.

      And yes, you’ll be hurt more if you’re hit by a bigger car at the same speed - but speed matters more (energy equals mass times velocity squared after all) and if the bigger car is able to stop faster, that means it’s more survivable, assuming the driver or some driver aid system does indeed try and slow down the car - if not, then the heavier car is for sure more dangerous.

      • observes_depths@aussie.zone
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        23 hours ago

        Bigger cars do WAY more damage. To pedestrians, the impact is higher on the body and far more lethal; and to other vehicles, well that’s obvious.

        I think you’re right though, with simplified physics the additional traction does cancel out the additional momentum.

        But wider tyres and expensive brakes actually don’t make a difference. More contact with the ground just reduces the traction per area, total traction hasn’t changed (assuming a smooth road). As for brakes, as long as they’re strong enough to lock the wheel, that’s enough. ABS helps a little, but expensive designs are only useful if you’re in a race.

        • boonhet@sopuli.xyz
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          15 hours ago

          Yet, performance cars with wider tires and bigger brakes (that don’t overheat and fade quickly) stop quicker than economy cars.

          • observes_depths@aussie.zone
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            11 hours ago

            If they do that’s probably softer tyres and aerodynamics. Maybe suspension and weight distribution. Many factors anyway.

    • bridgeenjoyer@sh.itjust.works
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      1 day ago

      Montana does this actually. Cars can do 60 for example, semis must go 50. Granted its not divided up for bro trucks and huge SUVs like it should be. Every state should. And speed limits slow down at night!

      • boonhet@sopuli.xyz
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        1 day ago

        The proper big brodozers (F350 at least, not sure about 250) are legally limited to 90 km/h in my country because if total weight (that includes the legally allowed cargo + passenger capacity, but not towing capacity) is over 3500 KG, it’s considered a heavy truck and same regulations apply as for a big ass lorry lol

        • bridgeenjoyer@sh.itjust.works
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          1 day ago

          Thats good at least. They should be illegal for normal joes IMO. Or have to be used for work once a week.

          I do have a truck myself. Only used for work. 8 ft bed. No ac or radio. A real work truck, not some fluffy bullshit Cadillac mom truck. And, my “truck” is still smaller than any of those pavement queens.

          Bring back wagons!!!